I would like to mention that Google own SPA framework, angular, has redirect routes which effectively do back button hijacking if used, because they add the url you're redirecting from to the history.
getAngular was an online JSON storage service. The guys reused their code when they went to work in DoubleClick at Google. Not made by Google not Google’s framework and plenty of Google people think it’s rubbish.
That's only because SPAs routing maybe internal for that particular app. In that case, the UI/UX to end user is *only* possible and smooth when they hijack the back button as such.